Preheat oven to 375 degrees F (190 degrees C). Line a 9x13-inch casserole dish with parchment paper.
Mix rolled oats, steel-cut oats, bananas, flax seeds, water, peanut butter, dates, pecans, chia seeds, coconut oil, vanilla extract, and salt together in a bowl; press into the prepared casserole dish. Drizzle honey over mixture.
Bake in the preheated oven until set, about 45 minutes. Cool completely before cutting into bars. Wrap bars in plastic wrap and freeze. Let defrost for 15 minutes before eating or heat in microwave.